<template>
  <div>message的值：{{ message }}</div>
  <div>obj.message的值：{{ obj.message }}</div>
</template>

<script setup>
import { reactive, toRefs } from 'vue'
const obj = reactive({ message: '盛年不重来，一日难再晨' })
let { message } = toRefs(obj)
setTimeout(() => {
  message.value = '及时当勉励，岁月不待人'
}, 2000)
</script>